variable-size character

BP neural network can implement approximating nonlinear functions by arbitrary accuracy through regulating variable weight connection. This character can fit the nonlinear functions relations.

BP神经网络通过调节连接权重可以实现以任意精度逼近非线性函数，利用这一特点可对非线性函数关系进行拟合。

The formation and development of Sun Yatsen's thought should be a variable process which some effective factors were living experiences, occident education, colonial outlook and his character feature, and connected with his goal-system.

孙中山早期思想的形成是一个变化发展的动态过程，早期的生活境遇、西式教育、殖民地观感、个性心理特征都是影响他思想形成的重要因素，也是与行为目标系统密切相关的。

The cognitive theory of stress suggests that coping, an important mediated variable, plays an important role between stressors and stress responses and influences the character and intensity of stress responses and regulates the relationship between stress and mental health.

应激认知理论认为，应对是应激源与应激反应之间重要的中介变量，它影响着应激反应的性质和强度，进而调控着应激同个体心身健康的关系。

In character they are as variable as the population at large.

在性格特征方面,他们和普通大众一样多种多样.

In this article, a compact structure and energy-saving variable frequency close hydraulic power unit is introduced. The control character of this unit using PID has studied. The response characteristic of the system has improved using PID control.

针对一种结构紧凑、节能的变频闭式液压动力单元进行了PID控制特性仿真研究，采用PID控制时能改善系统的的响应特性，使系统速度和压力达到预定的控制效果。